Taurine is named after the bull because it was first found in ox bile
Energy-drink cans advertise taurine, but its name is older and odder: German chemists first pulled it from ox bile in 1827, and taurus is Latin for bull. The body makes its own supply from sulfur amino acids, and humans have no official recommended intake. Cats, however, cannot do without it.
Taurine is usually lumped in with amino acids, but it carries a sulfonic acid group where protein-building amino acids have a carboxylic one, so it plays no part in making proteins and is absent from the genetic code. It is plentiful in mammalian organs and is a major ingredient of bile. The human liver builds it mainly from cysteine or methionine, oxidising cysteine step by step through an intermediate called hypotaurine. Land plants contain little or none, although some algae hold a lot.
Friedrich Tiedemann and Leopold Gmelin isolated it in 1827; Von H. Demarcay gave it its name in 1838, and Edmund Ronalds found it in human bile in 1846. Fish and meat are the natural dietary sources: one estimate puts average omnivore intake around 58 milligrams a day, while vegan diets supply little or none. Human milk contains it too, and since the early 1980s formula makers have often included it just to be safe, though nobody has rigorously tested whether babies need it.
Cats do have a dietary requirement, and because cooking and baking partly destroy taurine, pet food makers add it; dogs and poultry get supplements too. In 1993 commercial output was about 5,000 to 6,000 tonnes, split evenly between pet food and pharmaceuticals. Synthetic taurine is usually made from isethionic acid, itself derived from ethylene oxide and sodium bisulfite.
Energy drinks carry 1 to 3 grams per serving. A 2008 review found no documented health effects, good or bad, at those amounts. Good clinical trials are lacking, and early human studies suffered from small numbers and inconsistent doses. The European Food Safety Authority suggests intakes up to 6 grams a day may be safe, while other sources set the ceiling for healthy adults at 3 grams.
Source: Taurine
